Compression connector

ABSTRACT

A connector utilized to electrically connect together conductive pads disposed on different substrates includes a flexible substrate having a plurality of conductive through-holes therein. A conductive line formed in the flexible substrate extends between at least two of the conductive through-holes. A plurality of contacts are mounted in the conductive through-holes of the flexible substrate. Each contact includes a post connected to a base of a crown-shaped head having a plurality of projections around the periphery of the base that extend away from the base in the direction opposite the post. The post of each contact is soldered into one of the plurality of conductive through-holes. A compression mat positioned on a side of the flexible substrate opposite the crown-shaped heads includes a plurality of resilient cylinders that extend away from a resilient base. Each resilient cylinder has a distal end alignable in registration with a distal end of the post of one of the plurality of contacts. A compression fitting is positionable adjacent the resilient base of the compression mat. The compression fitting co-acts with one of the substrates to apply a clamping force therebetween that urges a projection of each contact into electrical contact with one of the conductive pads.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to electrical connectors and, more particularly,to high density electrical connectors utilized to electrically connectelectronic devices disposed on two or more printed circuit boards.

2. Description of the Prior Art

Increased integration of electronic devices has created aninterconnection problem for printed circuit boards receiving thesedevices. Specifically, the number of interconnections required toelectrically connect together two or more printed circuit boardsreceiving these electronic devices has exceeded the connection densitiesof prior art pin-in-socket connectors. Moreover, these prior artpin-in-socket connectors typically have relatively long and unshieldedlengths which have uncontrolled impedances resulting in less thandesired electrical performance.

A high contact density connector utilizable for electrically connectingtogether electronic devices received on two or more printed circuitboards and overcoming the foregoing problems is disclosed in an articleentitled "A High Density Edge Connector" by J. Campbell et al.,Copyright 1995 IEEE. This article discloses a flex circuit formed of a 2mil thick polyimide film having 3 mil wide copper lines plated onto oneside thereof and 25 mil round contact pads plated on the side of thefilm opposite the circuit lines and along both edges of the film 4 mildiameter plated through-holes, or vias, extend between the contact padson one side of the film and the circuit lines on the other side.Palladium dendrites, or spires, are electro-deposited on surfaces ofeach contact pad. These dendrites straddle dust or fibers and punctureoils or films present on each contact pad prior to connector mating andproduce on each contact pad a multitude of conductive connections. Theconnector includes a molded plastic force block to which elastomericcylinders are molded These cylinders act as springs which provide force,when compressed during assembly, to make and maintain an electricalconnection between the contact pads on the film and the pads on aprinted circuit board. One cylinder is provided for each contact andcompensates for any variation in planarity and tolerance accumulation.Conical alignment pins are utilized to mate alignment holes in the flexcircuit with alignment holes in the printed circuit board duringassembly, thereby ensuring proper registration between the contact padson the film and the pads on the printed circuit board.

Another flexible circuit connector for connecting a daughter card and amother board is disclosed in an article entitled "A High DensityPad-On-Pad Connector Utilizing A Flexible Circuit" by R. S. Pokrzywa,Copyright 1993 IEEE. This connector utilizes a two-sided flex circuithaving plated, spherical contacts contacting flat printed circuit padson the daughter card and on the mother board. The spherical contacts onthe flex circuit are 5 mils in diameter and have a copper base metaloverplated with nickel and gold. Alignment pins are utilized to alignthe flex circuit, the daughter card and the mother board so that eachspherical contact mates with a desired printed circuit pad.Precipitation hardened stainless steel curved beams provide contactforce for reliable connection between the spherical contacts and theprinted circuit pads. During actuation, the curved beam is flattened toproduce a uniform load across the contact area. An elastomeric pad ispositioned between the beam and the contact area to accommodate localdiscrepancies in load across the contact area and to focus the connectorforces. In one embodiment, the elastomeric pad has a plurality ofelastomeric cylinders utilized to back-up the spherical contacts. Inanother embodiment, where size does not permit molding individualcylinders for each spherical contact, an elastomeric rib is utilized toback a row of spherical contacts.

A problem with spherical contact pads and electro-deposited dendrites oncontact pads is that they inconsistently break through contaminants,such as oxides, films or foreign materials, that may be present thereonor on the contact pad of a printed circuit board. Hence, inadequateelectrical contact or, in some instances, no electrical contact is madebetween the contact pad of the flexible circuit and the contact pad ofthe printed circuit board. Moreover, the formation of dendrites on thecontacts of the flexible circuit increases the cost of such connectors.

It is therefore an object the present invention to provide a connectorwhich overcomes these drawbacks of the prior art connectors. It is anobject of the present invention to provide a compression connectorcontact that promotes electrical contact with a conductive pad of aprinted circuit board. It is an object of the present invention toprovide a method for making a connector that utilizes the providedcompression connector contact. It is an object of the present inventionto provide a method of making a flexible circuit connector that is lesscostly to manufacture than the prior art flex circuit connectors.

SUMMARY OF THE INVENTION

Accordingly, we have invented a compression connector utilized toelectrically connect together conductive pads disposed on one or moresubstrates. The compression connector includes a flexible substratehaving a plurality of conductive through-holes therein and at least oneconductive line thereon extending between at least two of the conductivethrough-holes. The compression connector also includes a plurality ofcontacts. Each contact has a post connected to a base of a crown-shapedhead having a plurality of projections around the periphery of the basethat extend away from the base in a direction opposite the post. Thepost of each contact is secured in one of the plurality of conductivethrough-holes.

A compression mat can be positioned on the side of the flexiblesubstrate opposite the crown-shaped heads of the plurality of contacts.The compression mat can include a plurality of resilient cylindersextending away from a resilient base. Each resilient cylinder can have adistal end alignable in registration with a distal end of the post ofone of the plurality of contacts secured in one of the plurality ofconductive through-holes.

A transfer film can be utilized to transfer the plurality of contacts tothe flexible substrate prior to securing each post in one of theplurality of conductive through-holes. The transfer film preferably hasa plurality of elastically deformable receiving apertures which receiveand secure the crown-shaped heads of the plurality of contacts.

The compression connector can also include a rigid substrate, such as aprinted circuit board, which has a plurality of the conductive pads on asurface thereof and at least one conductive line connected to at leastone of the conductive pads. The rigid substrate and the flexiblesubstrate are alignable so that at least one projection of each contacton the flexible substrate is aligned in registration with one of theconductive pads on the surface of the rigid substrate.

A compression fitting can be positionable adjacent the resilient base ofthe compression mat. The compression fitting forces together at leastone projection of each contact and the conductive pad in registrationtherewith. Each resilient column of the compression mat contacts thedistal end of a post of a contact and functions as the spring whencompressed to make and maintain good electrical connection between theprojection and the conductive pad.

Preferably, a plurality of alignment holes in each of the flexiblesubstrate, the rigid substrate and the compression fitting co-act with alike plurality of alignment pins to align the flexible substrate, therigid substrate and the compression fitting so that the heads of theplurality of contacts are in registration with the plurality of contactpads. Each alignment pin is preferably a bolt having a threaded endadapted to mate with a threaded nut.

We have invented a compression connector contact that includes acrown-shaped head having a base and a plurality of projections disposedaround the periphery of the base and extending to one side thereof. Apost extends from the side of the base opposite the projections.

The side of the base opposite the post can have a cavity formed thereinin registration with a lengthwise axis of the post. The base can have aperiphery having a generally rectangular outline. Each corner of thegenerally rectangular outline of the base can be rounded and can includeone of the plurality of projections. Each projection can have a roundededge formed continuous with the periphery of the base.

We have also invented a method of making a connector that includesproviding a plurality of contacts, each contact having a post connectedto a base of a crown-shaped head. Each crown-shaped head has a pluralityof projections around the periphery of the base that extends away fromthe base in a direction opposite the post. The crown-shaped heads of theplurality of contacts are inserted into a plurality of receivingapertures in a transfer film so that the posts extend out of theplurality of receiving apertures. A flexible substrate is providedhaving a plurality of conductive through-holes therein and a pluralityof conductive lines thereon. At least one conductive line extendsbetween and electrically connects at least two of the conductivethrough-holes. The transfer film and the flexible substrate are mated sothat the posts of the plurality of contacts are received in theplurality of conductive through-holes in the flexible substrate. Theposts of the plurality of contacts are fused to the plurality ofconductive through-holes in the flexible substrate. The transfer film isthen separated from the flexible substrate and the plurality ofcontacts.

The plurality of contacts are formed from a strip of conductivematerial. Each contact is connected to an adjacent contact by a ribformed from the conductive strip. Each contact is excised from itsconnecting rib and inserted into one of the receiving apertures in thetransfer film. Each receiving aperture elastically deforms to receiveand retain the head of the contact therein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a cross section of a compression connector in accordance withthe present invention;

FIG. 1b is an enlarged view of a portion of FIG. 1a within line 1b;

FIG. 2a is a plan view of a compression mat of the compression connectorin FIG. 1;

FIG. 2b is a side view of the compression mat of FIG. 2a;

FIG. 3a is a plan view of a flexible substrate used in the compressionconnector of FIG. 1;

FIG. 3b is an enlarged view of a portion of FIG. 3a within line 3b;

FIG. 4a is a plan view of a conductive strip that has been formed toinclude a plurality of contacts that are utilized in the compressionconnector of FIG. 1;

FIG. 4b is an enlarged view of a portion of the conductive strip of FIG.4a within line 4b;

FIG. 4c is a cross section taken along lines 4c--4c in FIG. 4b;

FIG. 5 is a plan view of the conductive strip of FIG. 4a aligned with atransfer film;

FIG. 6 is a cross section of the aligned conductive strip and transferfilm of FIG. 5 positioned between a transfer base and an excising tool;

FIG. 7 is a cross section of the contacts of the conductive strip ofFIG. 4a received in receiving apertures of the transfer film of FIG. 6and positioned in alignment with through-holes formed in the flexiblesubstrate of FIG. 3a;

FIG. 8 is a cross section similar to FIG. 7 showing the transfer filmand flexible substrate mated together with the posts of the contactsreceived within and soldered to the through-holes of the flexiblesubstrate; and

FIG. 9 is a cross section similar to FIGS. 7 and 8 and showing theseparation of the transfer film from the flexible substrate andcontacts.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1a-1b, a rigid substrate 2, such as a printed circuitboard formed of FR-4 or ceramic, has a plurality of conductive pads 4formed thereon in a manner known in the art. The rigid substrate 2 mayinclude one or more conductive lines that extend between one or more ofthe conductive pads 4 or between a conductive pad 4 and an electronicdevice connected to the rigid substrate 2. The conductive lines andelectronic device are not shown on the rigid substrate 2 in FIGS. 1a-1bfor simplicity of illustration.

A flexible insulating substrate 6 having a plurality of contacts 8secured thereon is positioned adjacent the rigid substrate 2. Theflexible substrate 6 is preferably formed of a polyimide film such asKapton®. Kapton® is a registered trademark of E.I. DuPont DeNemours &Company. The contacts 8 are secured on the flexible substrate 6 in apattern matching the pattern of the conductive pads 4 on the rigidsubstrate 2. Each contact 8 includes a head 10 that extends away from asurface of the flexible substrate 6. Aligning the flexible substrate 6and the rigid substrate 2 positions the heads 10 in registration withthe conductive pads 4.

A compression fitting 12 is positioned on the side of the flexiblesubstrate 6 opposite the heads 10 of the contacts 8. The compressionfitting 12 includes a compression mat 14 received in an aperture 15 ofan alignment sleeve 16. As shown in FIGS. 2a-2b, the compression mat 14includes a resilient base 18, preferably having a generally rectangularoutline, and a plurality of resilient cylinders 20 extending from theresilient base 18. The compression mat 14 and the flexible substrate 6are positioned so that distal ends of the resilient cylinders 20 arealigned in registration with the contacts 8 on a surface of the flexiblesubstrate 6 opposite the heads 10. The compression fitting 12 includes awasher 22 positioned on a side of the alignment sleeve 16 opposite theresilient base 18 of the compression mat 14. Preferably, the compressionmat 14 is formed of a thermal silicon rubber, the alignment sleeve 16 isformed from a polyphenylene sulfide, UL 94 V-0, and the washer 22 isformed from stainless steel.

The compression fitting 12, the flexible substrate 6 and the rigidsubstrate 2 each have a plurality of alignment apertures 24, 26 and 28,respectively. Each alignment aperture 24, 26 and 28 is adapted toreceive a shaft of an alignment pin 30, such as a bolt having anexternally threaded end 31 adapted to mate with internal threads of anut 32. Applying the nuts 32 to the alignment pins 30 urges together thecompression fitting 12 and the rigid substrate 2. This urging togetherforces into contact the conductive pads 4 and the heads 10 inregistration therewith, and the distal ends of the resilient cylinders20 in registration with contacts 8 on the surface of the flexiblesubstrate 6 opposite the heads 10. Continued application of the nuts 32to the alignment pins 30 compresses the compression mat 14 between theflexible substrate 6 and the washer 22. This compression causes theresilient cylinders 20 to deform against the contacts 8 on the side ofthe flexible substrate 6 opposite the heads 10. This deformation causeseach resilient cylinder 20 to apply a spring force between the head 10and the conductive pad 4 in registration therewith. This spring forcepromotes between the head 10 and the conductive pad 4 in registrationtherewith the formation and maintenance of good electrical contact andcompensates for any variations in planarity and tolerance accumulation.Preferably, double-sided tape 34 is utilized to adhere together adjacentsurface of flexible substrate 6 and the sides of the alignment sleeve16.

The head 10 of each contact 8 has a base 40 and a plurality ofprojections 42 disposed around a periphery 43 of the base 40. Theprojections 42 extend to one side of the base 40 and give the head 10 acrown-shaped appearance. Each contact 8 also has a post 44 that extendsfrom a central part of the base 40 opposite the projections 42. A cavity46 is preferably formed in each base 40 opposite the post 44 and inalignment with a lengthwise axis 47 of the post 44.

With reference to FIGS. 3a-3b and with ongoing reference to FIGS. 1a-1b,the flexible substrate 6 has a plurality of through-holes 48 formedtherein that are adapted to receive the posts 44 of the contacts 8. Thewall of each through-hole 48 includes metallization 50 formed therein toform a conductive through-hole. The metallization 50 in eachthrough-hole 48 is preferably connected to a conductive line 52 or toone or more conductive ground planes 53 formed on the flexible substrate6. The one or more conductive ground planes 53 are formed on one or bothsurfaces of the flexible substrate 6 to reduce or eliminate cross-talkbetween conductive lines 52 and/or to reduce or eliminate the effect onone or more of the conductive lines 52 of electromagnetic interferencefrom external sources. The metallization 50 in each through-hole 48, theconductive lines 52 and the conductive ground planes 53 are formed onthe flexible substrate 6 in a manner known in the art. To maintain thepost 44 of each contact 8 received in a through-hole 48, themetallization 50 of each through-hole 48 and the posts 44 of thecontacts 8 received therein are fused together, preferably utilizing asolder 54.

With reference to FIGS. 4a-4c, an array of contacts 8 is formed byexposing a thin, flat strip 60 of conductive material to a stampingoperation. The stamping operation also forms from the strip 60 aplurality of ribs 62 that extend between and secure together adjacentcontacts 8.

In a preferred embodiment, the periphery 43 of the base 40 of each head10 has a generally rectangular outline. Each corner 66 of the generallyrectangular outline of the base 40 is rounded and includes one of theprojections 42. Each projection 42 has a rounded edge 68 formedcontinuous with the periphery 43 of the base 40.

With reference to FIG. 5, to install the contacts 8 in the flexiblesubstrate 6, the contacts 8 are first transferred to a flexible transferfilm 70, such as Kapton®. More specifically, the strip 60 having thearray of contacts 8 formed therein is aligned with the transfer film 70so that each contact 8 is aligned in registration with one of aplurality of receiving apertures 72 in the transfer film 70.

As shown in FIG. 6, the transfer film 70 is positioned between the strip60 and a transfer base 76 so that the posts 44 of the contacts 8 arepositioned in opposition with the transfer base 76 through the receivingapertures 72 of the transfer film 70. An excising tool 78 having aplurality of blades 80 and a plurality of push pins 82 is positioned ona side of the conductive strip 60 opposite the transfer film 70. In use,the excising tool 78 is moved towards the base 76 so that the blades 80excise the contacts 8 from the ribs 62. The excised contacts 8 are theninserted into the receiving apertures 72 by the push pins 82 so that thelengthwise axes 47 of the posts 44 are substantially coaxial withlengthwise axes 83 of the receiving apertures 72.

Before inserting the contacts 8, each receiving aperture 72 has adiameter 84 that is less than a diagonal distance 86 (shown in FIG. 4c)between opposite corners 66 of the base 40. As shown in FIG. 7, thereceiving apertures 72 elastically deform to receive and secure theheads 10 of the contacts 8 therein. Preferably, each head 10 has aheight 88 (shown in FIG. 4c) that is greater than a thickness 90 of thetransfer film 70. Hence, when the heads 10 are inserted in the receivingapertures 72, the posts 44 of the contacts 8 are preferably positionedoutside the receiving apertures 72. When the heads 10 are received inthe receiving apertures 72, the transfer film 70 and the flexiblesubstrate 6 are positioned so that the posts 44 are in registration withand receivable in the through-holes 48.

As shown in FIG. 8, the flexible substrate 6 and the transfer film 70are brought together so that the posts 44 are received within themetallization 50 of the through-holes 48. The contacts 8 are secured tothe flexible substrate 6 by fusing the posts 44 and the metallization 50of the through-holes 48 together with the solder 54.

As shown in FIG. 9, the flexibility of the transfer film 70 and theelastic deformability of the receiving apertures 72 enables the transferfilm 70 to be separated, e.g., peeled away, from the contacts 8 securedto the flexible substrate 6. When the transfer film 70 is separated, theflexible substrate 6 and contacts 8 can be utilized in the mannerdescribed above in connection with FIGS. 1a-1b.

As shown in FIG. 3a, a first plurality 96 of through-holes 48 and asecond plurality 98 of through-holes 48 are preferably disposed onopposite sides of the flexible substrate 6. When the contacts 8 arefused into the first and second plurality 96, 98 of through-holes 48,the side of the flexible substrate 6 adjacent the first plurality 96 ofthrough-holes 48 can be utilized to connect to one rigid substrate (notshown) and the side of the flexible substrate 6 adjacent the secondplurality 98 of through-holes 48 can be utilized to connect to anotherrigid substrate (not shown) thereby effecting electrical connectionbetween the rigid substrates.

In a preferred embodiment, each post 44 has a diameter between 7 and 8mils and a length of 2 mils. The head 10 of each contact 8 has a heightof 10 mils and the cavity 46 has a depth of 3 mils. The height of eachprojection 42 is 4 mils and a distance 94 (shown in FIG. 9) betweenrounded edges 68 of projections 42 on diagonally opposite corner 66 is21.5 mils. The strip 60 and contacts 8 are formed from a strip of 1/4hard brass. The contacts 8 are plated with 5 micro-inches of soft goldover 30 micro-inches of palladium nickel over 50 micro-inches ofsulfamate nickel. The conductors 52 and the ground planes 53 of theflexible substrate 6 are formed from 1/2 ounce copper which is depositedas a sheet on the flexible substrate 6 and then patterned and etchedutilizing photolithographic and etching techniques known in the art.

Based on the foregoing, it can be seen that the contacts 8 aresufficiently small so that manual manipulation of contacts 8 into thethrough-holes 48 of the flexible substrate 6 is not practical. To thisend, and in accordance with the present invention, forming the array ofcontacts 8 from the strip 60 enables the contacts 8 to be manipulated asan array. Similarly, the transfer film 70 enables the contacts 8 to betransferred as an array from the strip 60 to the flexible substrate 6.The transfer film 70 also helps maintain the posts 44 of the contacts 8in the through-holes 48 during fusing of the posts 44 to themetallization 50 of the through-holes 48. Hence, the contacts 8 aremanipulated as an array from the time they are formed from the strip 60in the stamping operation until they are fused into the conductivethrough-holes in the flexible substrate 6. This manipulation of thecontacts 8 as an array enables the compression connector of the presentinvention to be manufactured efficiently and cost effectively. Moreover,the compression connector of the present invention avoids the prior artteaching of plating contacts on the flexible substrate.

Because the metallization 50 in the through-holes 48 and the conductivelines 52 are pre-formed on the flexible substrate 6, it is preferable toavoid soldering the contacts 8 to the through-holes 48 prior to excisingthe contacts from the ribs 62 due to concerns over cutting with theblades 80 of the excising tool 78 the conductive lines 52 or themetallization 50 in the through-holes 48. Hence, the contacts 8 arefirst transferred to the flexible transfer film 70 which is utilized totransfer the contacts 8 to the flexible substrate 6 and which maythereafter be disposed as justified by the condition thereof.

The contacts 8 of the present invention are believed to provide overprior contacts improved contact with contact pads 4 on the rigidsubstrate 2. Specifically, the rounded edge 68 of each projection 42contacting one of the contact pads 4 cuts through oils or films that maybe present on the conductive pad 4 and/or the contact 8 prior to mating,thereby enabling conductive paths to be formed between each projection42 in contact with the conductive pad 4.

As can be seen from the foregoing, the present invention provides acompression connector contact that promotes electrical contact with aconductive pad of a printed circuit board. The present invention alsoprovides a method for making a flexible circuit connector that utilizesthe provided compression connector contact and is less costly tomanufacture than the prior art flexible circuit connectors.

The invention has been described with reference to the preferredembodiment. Obvious modifications and alterations will occur to othersupon reading and understanding the preceding specification. It isintended that the invention be construed as including all suchmodifications and alterations insofar as they come within the scope ofthe appended claims or the equivalents thereof.

We claim:
 1. A compression connector utilized to electrically connecttogether conductive pads disposed on one or more substrates, theconnector comprising:a flexible insulating substrate having a pluralityof conductive through-holes therein and at least one conductive linethereon extending between at least two of the conductive through-holes;and a plurality of contacts formed in a stamping operation, each contacthaving a post connected to a base of a crown-shaped head having aplurality of projections around the periphery of the base that extendaway from the base in a direction opposite the post, the post of eachcontact secured in one of the plurality of conductive through-holes. 2.The compression connector as set forth in claim 1, further including:acompression mat having a plurality of resilient columns extending awayfrom a resilient base, each resilient column having a distal endalignable in registration with a distal end of a post of one of theplurality of contacts, each distal end of each resilient column incontact with at least one of (i) the distal end of the post inregistration therewith and (ii) a solder used to secure the post inregistration therewith in the one of the plurality of conductivethrough-holes, when the flexible insulating substrate and thecompression mat are in compression.
 3. The compression connector as setforth in claim 1, further including:a transfer film having a pluralityof elastically deformable receiving apertures which receive thecrown-shaped heads of the plurality of contacts, each receiving aperturesecuring the crown-shaped head of the contact received therein so thatthe post thereof is positioned outside the receiving aperture.
 4. Thecompression connector as set forth in claim 1, further including:a rigidsubstrate having a plurality of conductive pads on a surface thereof andat least one conductive line connected to at least one of the conductivepads, wherein aligning the rigid substrate and the flexible substratealigns at least one projection of one of the contacts secured to theflexible substrate in registration with one of the conductive pads onthe surface of the rigid substrate.
 5. The compression connector as setforth in claim 4, further including:a compression fitting which forcestogether the at least one projection of the one of the contacts and theconductive pad in registration therewith.
 6. The compression connectoras set forth in claim 5, further including:a plurality of alignmentholes in each of the flexible substrate, the rigid substrate and thecompression fitting; and a plurality of alignment pins, each alignmentpin receivable through one of the plurality of alignment holes in eachof the flexible substrate, the rigid substrate and the compressionfitting, wherein: the alignment holes and the alignment pins co-act toalign the flexible substrate, the rigid substrate and the compressionfitting so that the heads of the plurality of contacts are aligned inregistration with the plurality of contact pads.
 7. The compressionconnector as set forth in claim 6, wherein:the alignment pins are bolts,each bolt having a threaded end with external threads adapted to matewith internal threads of a threaded nut; and applying the nuts to thebolts urges the compression fitting and the rigid substrate together sothat the at least one projection of the one of the contacts and theconductive pad in registration therewith are forced together.
 8. Acompression connector contact formed from a strip of conductive materialin a stamping operation, the compression connector contact comprising:acrown-shaped head having a base and a plurality of projections disposedaround the periphery of the base and extending to one side thereof; anda post extending from the side of the base opposite the projections. 9.The compression connector as set forth in claim 8, further including onthe side of the base opposite the post a cavity in registration with alengthwise axis of the post.
 10. The compression connector as set forthin claim 8, wherein:the base has a periphery having a generallyrectangular outline; and each corner of the generally rectangularoutline of the base is rounded.
 11. The compression connector as setforth in claim 10, wherein:each corner of the outline of the baseincludes one of the plurality of projections; and each projection has arounded edge formed continuous with the periphery of the base.
 12. Acompression connector comprising:a flexible substrate having aconductive line formed thereon; a contact formed from a strip ofconductive material in a stamping operation apart from the flexiblesubstrate and connectable to the flexible substrate in electricalcontact with the conductive line thereon; and a rigid substrate having aconductive line thereon, the rigid substrate and the flexible substratepositionable so that the contact electrically connects the conductiveline on the flexible substrate with the conductive line on the rigidsubstrate.
 13. The compression connector as set forth in claim 12,wherein:the rigid substrate includes thereon a conductive pad inelectrical contact with the conductive line on the rigid substrate; andthe rigid substrate and the flexible substrate are positionable so thatthe contact connected to the flexible substrate contacts the conductivepad on the rigid substrate.
 14. The compression connector as set forthin claim 12, wherein the contact is formed by stamping a thin and flatstrip of conductive material.
 15. The compression connector as set forthin claim 12, wherein the contact has a crown-shaped head which includesa plurality of projections disposed around a periphery of the head andextending to one side of the head.
 16. The compression connector as setforth in claim 15, wherein:the contact has a post extending from thehead in a direction opposite the plurality of projections; and the postis receivable in a through-hole formed in the flexible substrate. 17.The compression connector as set forth in claim 15, wherein:the headincludes a base having a generally rectangular outline; and one of theplurality of projections is disposed at each corner of the generallyrectangular outline of the base.